Signaling system



P 1941- A. R. BONORDEN 2,255,595

SIGNALING SYSTEM Filed Feb. 25, 1959 4 Sheets-Sheet 1 BUFFALO PHIL ADEL PHIA v l/ENTOR A. R. B ONORDE N ATTpRA/Er Sept. 9, 1941.

A. R. BONORIDEN SIGNALING SYSTEM Filed Feb. 25, 1959 4 Sheets-Sheet 2 mim m P Nk M/VE/v TOR 4. R. BO/VORDE/V A T TOR/V5 V Sept. 9, 1941 I A. R. BONORDEN 2,255,595

SIGNALING SYSTEM Filed Feb. 25,1939 4 Sheets-Sheet 3 E I I "at" /N l/E N TOR ARBONORDEN A TTORNEY S p 1941 A. R. BONORDEN V 2,255,595

SIGNALING SYSTEM Filed Feb. 25, 1939 4 Sheets-Sheet 4 USE MARS/MAL MARCIA/Al.

MARGINAL E /0 NUMBER OF REPETITIONS FIG.6

INVENTOR A. R. BONORDE N BY ATTORNEY Patented Sept. 9, 1941 UNITED STATES PATENT OFFICE SIGNALING SYSTEM Application February 25, 1939, Serial No. 258,547

18 Claims.

This invention relates to telegraph systems and particularly t systems wherein a common transmission channel is provided for a plurality of stations, any one of which may broadcast messages into said channel for simultaneous reception by all of said stations. The invention is an improvement on the system disclosed in Patent 2,111,685 granted March 22, 1938, to C. R. Walker.

In ring type circuits having even a measurable propagation time signals transmitted at one point in the ring will traverse the ring and return to such point and since they are not synchronous at the incoming and outgoing terminals of the station forming such point, must be separated. Hence, during transmission the normally closed connection between the incoming and outgoing terminals of the circuit must be opened. This has been done in various Ways all devised to either manually and according to schedule, or automatically, close the ring only after the last impulse has completely traversed the ring so as not to set up a traveling or stray impulse which will traverse the ring indefinitely. However, even though such means are efficient and effective, a

hit or accidental opening of the circuit for even an extremely short time interval will start a traveling stray impulse around the closed ring and which will be objectionable as it will operate the receiving apparatus at all the stations in some manner and make the circuit appear busy.

An object of the invention is to suppress any such traveling hit or useless signal while not interfering with the transmission of normal signals. Accordingly, a feature of the invention is a means to differentiate between a periodically recurring useless signal and normal transmission and means responsive thereto to suppress such useless signal. In one embodiment of the invention there is a means responsive to signals of this nature which acts to step a device forward step by step until a predetermined point is reached whereupon the switch causes the ring circuit to be opened for a length of time somewhat greater than the propagationtime of the ring. As a switch is being stepped forward to this point it will be returned to its starting point if character signals are received and the ring will not be opened and hence the means for opening the ring and suppressing the use of a signal only becomes effective after a predetermined period and in its action may be halted at any time previous thereto.

In accordance with another feature of the invention the number of forward steps to be taken and. useless traveling impuse.

by the step-by-step device may be readily altered so that auseless traveling signal may be suppressed in the shortest possible time consistent with the characteristics of the circuit and consistent with a desired use of the circuit.

In accordance with a further feature of the invention the step-by-step device may be constituted of an arrangement of relays well known as counting relays. 7

Another feature of the invention is a means differently responsive to spacing signals of different length whereby various-traffic conditions may be properly treated. For instance, the code for letters comprisesa spacing signal as a start pulse followed by five marking pulses constituting the code proper and a stop pulse which is also marking. Therefore the code for letters appears as a single and isolated spacing pulse which might easily be mistaken for a hit or unwanted But traffic conditions sometimes require that the code for letters be transmitted a number of times in succession and so unlessprovision were made to prevent it, the automatic means of this invention might cause the opening of the ring at the wrong time.

Accordingly, a feature oi the invention {is means to delay the opening of the ring in response to the repeated reception of a spacing signal of the exact'length of such a signal as used in the code for letters for a number of times in excess of any traiiic requirement. Since a hit or unwanted useless traveling impulse may be, of the exactlength of such a signal it must be suppressed if it continues beyond a given time.

As another instance, the code for the letter V constitutes a spacing signal as a starting been repeated a second time.

'be'suppressed if it persists.

As a further instance such a hit may be of such short duration that it does not simulate any known code and therefore it mustv be suppressed as soon as possible. Arrangements are therefore made to open the ring circuit and suppress. such a hit on the first repetition thereof.

Another feature of the invention is a quickimpulse. .shown is known as a hub circuit, generally circuit.

coming terminals is affected.

acting slow-releasing means for holding the circuit open after such means has been properly energized fora period somewhat longer than the propagation time of the ring.

The drawings comprise four sheets, the first sheet including Figs. 1 and 2, the second sheet including Figs. 3 and 4, the third sheet including Fig. 5, and the last sheet including Figs. 6 and 7.

Fig. 1 is a schematic diagram showing the general outline of a ring type circuit;

Fig. 2 is a circuit diagram showing one form;

of the invention in which a moving arm is caused to move forward step by step for a predetermined number of steps in order to cause circuit changes which will result in the suppression of a traveling useless impulse;

Figs. 3-and 4, together, form a circuit diagram' showing a station circuit in aring type system in which a step-by-step switch is employed for causing circuit changes to suppress a useless The type of telegraph circuit herein described in the Kinkead et al. Patent No.

Figs. 3 and 5, together, form another circuit diagram showing the, use of counting relays as step-by-step device for suppressing a useless I traveling signal;

for instance, New York, Boston, Albany, Bufialo,

Pittsburgh and Philadelphia. The small rectangle'l represents other apparatus of an electrical time consuming nature, such as a repeater.

Extending from the station circuit 1 there are shown in the usual manner, two subscribers .stations .8 and 9 each having receiving apparatus represented by a magnet and sending apparatus represented by transmitting contacts, though it is not necessary to use this exact combination at any local subscribers station as will appear hereinafter. In a system of this nature transmission from one of the subscribers stations entering the stationlcircuit will proceed in the direction indicated, by the arrow through stations 2,-3, 4, '5 and 6 and will in time return to the station circuit ,l. Ring circuits of this type have. 1 a definite and measurable propagation time depending partly on the length of the circuit print local copy but will form no check on the continuity of the ring. In case it is desired, a duplicate apparatus may be installed at any subscribers station so that he will have both local p the right-hand marking contact of slow-releasing and partly on the amount of apparatus included therein., In some cases it is desired to have the 1 receiving apparatus connected to the incoming 1 terminals, then the transmission sent from a :station has to traverse the entire ring before it 'afiects such receiving apparatus.

In doingso, however, it forms a check on the continuity on the whole circuit.

In Fig. 2 this feature is illustrated' by showing the receiving magnet 10 connected to the incoming terminals H so that transmission from the l .transmitting contacts [2 going out over the outgoing'terminals l3 will have to traverse the entire ring. beforerthe apparatus connected to the in- Inv the case of another station l4, illustrated, in. Fig., 2, the

efiectively. connected to theoutgoing terminals 1 I3. .The"receivingapparatus in. this casewill relay [8, the lower winding of relay I9, out over the transmitting contacts i6 of local subscribers station I4, the transmitting contacts l2 of local subscribers station 36, the lower winding of relay 20 to 'battery and ground. Relay w'will, therefore, respond in the same way as relay i1 and repeat the'impulses from the incoming terminals H to the outgoing terminals 13. I

Relay 2| is connected to this circuit but is slow to operate and will not respond to impulses representing ordinary trafiic conditions. As will appear hereinafter this relay will respond to a longbreak or an open circuit in line H which simulates a prolonged spacing signal. Thus impulses being transmitted over the ring will pass through the station circuit of Fig. 2 without afiecting anything other than relay I7 and the receiving magnets such as l0, l5 and 35.

When the transmitting contacts I2 or the transmittingcontacts I6 are being operated relay is will respond and by moving its armature to its left-hand or spacing contact will cause the operation of slow-releasing relay Hi. This relay efiectively opens'the ring circuit so that the impulses transmitted from the transmitting contacts [2 or I6 will not get back in to affect the incoming line I l except and until they have traversed the entire ring. In this case, the receiving magnets 19 and 35 will respond to transmission around the ring but receiving magnet .l5 which is not connected to the incoming line will respond only vto the outgoing transmission. Relay i8 is made slow to release and is timed to .:be slightly slower than the propagation time of the entire ring so that it will maintain an open circuit in the ring until the last spacing impulse sent by the transmitting contacts l2 or 16 has been transmitted entirely around the ring When the transmission has ceased, therefore, relay I9 will move to its right-hand or marking contact thereby allowing the slow-releasing relay l8 to also move its armature to its right-hand or .marking contact, thus closing the ring circuit.

It is evident that extraneous hits or short spacing impulses of a useless nature impressed upon the circuit at any point willzcontinue to be transmitted around the circuit indefinitely except that any inherent bias in repetition may either cause the space signal to diminish to zero length leaving the circuit in amarking condition afteran indefinite length of time or may increase its length until the entire circuit is in a spacing condition. It is a purpose of this invention to provide means to prevent this condition and to clear, out such a hit in a few seconds.

The receiving magnet 35 is enclosed within a broken-line rectangle 22 representingteletypewriter, receiving apparatus. In this machine, onlyone of which need be included in the ring circuit, there are two contact-actuating lugs or pull bars..23 and 24 which are. operated inla wellknownmanner. The lug :23, moves. downwardly and closes its associated contact only when the signal for "letters has been received by the magnet 35, while the lug 24 moves downwardly and closes its associated contact whenever any other character or signal is received by the magnet 35. Since the code for letters is closely simulated by a single spacing impulse the contacts closed by the lug 23 will be closed whenever a hit or open circuit of short duration is transmitted over the ring circuit and enters this circuit station through the incoming terminals H.

If the ring circuit is completely closed, that is, if no relay corresponding to relay I8 is operated to its spacing contact and no transmitting contacts, such as l2, are being operated, and a short momentary open circuit or hit occurs, this would, without the means herein provided, be transmitted about the ring indefinitely and consequently all the teletypewriters in the circuit would be operated periodically as though a letters code were being sent. In this case, with the relay 25 deenergized, acircuit will be closed periodically from battery through the contacts controlled by lug 23, the armature and back contact of relay 25 through stepping magnet 25 to ground whereby the stepping magnet will cause the arm 27 to advance step by step. After advancing one step the contacts controlled by lug 28 will be operated so as to place the release relay 29 in a circuit ready for operation at some later time. If this hit or single spacing continues to traverse the ring the arm 21 will finally strike lug 30 and close a contact to operate relay 3!. It should be noted that the number of steps which arm 21 is caused to take before striking the lug 30 may be varied in any well-known manner, such for instance, as by having the contacts carrying the lug 38 mounted on an adjustable support carried on the scale 31.

Relay 3i by its inner armature causes the operation of slow-release relay l8 which opens the ring to prevent the traveling impulse when it next returns from being relayed from the incoming line I I to the outgoing line l3. Through its outer armature relay 3! closes a circuit from battery through the contacts'controlled by lug 28 through the release magnet 29 which allows the arm 21 to return to normal, thus opening both pairs of contacts controlled by lugs 28 and 3B. Relay 3! is deenergized but being slow to release holds the circuit of relay l8 closed for a short time and relay iii in turn, being also slow to release, holds the ring circuit open for a period slightly greater than the propagation time of the ring so that the traveling impulse is efiectively stopped.

In order to prevent the opening of the ring circuit through chance sending of the letters signal or through the actual transmission of a series of letters signals the lug 24 operated by all other characters will cause the operation of relay 32. Relay 32 renders the grid of vacuum tube 33 positive so that relay 25 becomes energized and thus opens the circuit for the stepping magnet 26. If during regular and legitimate transmission the letters signal occurs the movement of lug 23 will not step the arm 2'! but will substitute a battery connection to the grid of tube 33 for that supplied by the inner armature of relay 32. A condenser 34 is connected to the grid circuit of vacuum tube 33 to render the vacuum tube circuit slow in releasing, and this may be timed in accordance with the propagation time of the ring circuit. r

Any time that the arm 27 has been moved from its normal position to an intermediate position and regular transmission operates the lug 24, the consequent operation. of relay 32 will cause, the release magnet '29 to be energized to return the arm 21 to normal.

In case a break signal which takes the form of a prolonged spacing signal enters the station circuit by way of the incoming line H, relay H- will be driven to its spacing contact and, after a period the slow-operating relay 2| will move its armature to its spacing contact so as to prevent the sustained operation of slow-release relay 18 by the operator at the keyboard [6 or [2. The spacing signal set up by relay I? will, therefore, appear as a break signal to the operator at station M. An operator at station 36 Willreceive the break directly from relay I1.

Figs. 3 and 4 taken together as shown on the second sheet of the drawings constitute a station circuit having incoming carrier channel terminals 40 and outgoing carrier channel terminals 4!. Connected to the outgoing terminal M is a source of signaling current 42 which is converted into spacing and marking signals by the operation of sending relay 43. Signals of this same nature will operate the receiving relay 44 in the well-known manner. Incoming signals, therefore operate the receiving relay 44 and this in turn operates a relay 45 which places a ground connection for spacing signals and a negative battery for a marking signal on the incoming hub circuit 45. These spacing and marking conditions affect the relay 4'! through its upper winding and this relay in turn places a ground connection for spacing signals and a negative battery connection through its lower winding and the winding of relay 48 for marking signals on the outgoing hub 45. The upper Winding of sending relay 43 being connected to the hub'49 will, therefore, repeat into the outgoing terminals 4| those signals which come in over the incoming terminals 46 and afiect the receiving relay 44.

Also connected to the hub 49 is a station circult for operating the local subscribers station 59. Spacing and marking conditions on the hub 49 are transmitted through the armature of polarized relay 5| and thence through thelower winding of sending relay 52 which, in turn, transmits corresponding spacing and marking signals over its armature through the upper winding of relay 5!, thence over the receiving magnet 53 and the transmitting contacts 54 of the local subscribers station 5K] to battery.

Another local subscribers station'55 is shown, this one having only teletypewriter receiving apparatus. No provision is made for transmission from this station so that various types of commercial arrangements are therefore illustrated. The receiving magnet 56 of this station 55 is operated by sending relay 5'! whose upper winding is connected to the hub 46. Therefore, it will appear that the local subscribers station 55 will respond directly to impulses coming in over the incoming terminals 40 whereas the receiving apparatus of the local subscribers station 59 will get so-called local copy when this station originates signals and will not respond to such signals after they have traversed the entire ring. Station will, of course, respond to all signals originated at other stations in the ring circuit.

When the subscriber at station transmits,

then the receiving relay 5! will operate and will 7 cause the operation of sending relay 43 to transthe ring is efiectively opened at this point and signals coming in over the incoming terminals 49 are. not repeated to the outgoing terminals 4!. Therefore, when the subscriber at station 59 is transmitting, his magnet 53 will immediately re spond to his transmission but will not respond to the same transmission after. it has traversed the entire ring and come in over the incoming terminals 40. of condenser 18 and resistance 89'the vacuum tube 58 is adjusted to hold relay 59 energized for a period after the release of relay 48 somewhat longer than the propagation time of the ring circuit. Under normal conditions when the subscriber at station 50 has ceased to operate his transmitting contacts 54 vacuum tube 58 will therefore hold relay 59 operated for a period somewhat longer than the propagation time of the ring so that relay 6| will effectively hold the ring circuit opened for such 'a period after transmission has ceased.

Local subscribers station 55 being effectively connected to the incoming hub 46 will respond only to the transmission from station 50 after it has entirely traversed the ring.

Space signals appearing on hub 46 .from the incoming terminal 49 cause relay 62 to operate. This opens a minus battery connection to the grid of tube63 but due to the connection of com denser 19 and potentiometer resistances 8| and 82 the grid does not immediately become sufliciently positive to cause relay 50 to operate. The timing of this operation depends on the value of condenser 19 and resistancesBl and 82 and may, for instance, be made as long as twice the propagation time of the ring circuit. If this condition occurs while the subscriber at station 1 59 is operating his transmitting contacts 54, re-' lays 59 and GI will be operated'so that nowv when relay 69 operates from tube 63 it will cause relay 6| to release, again connecting hub 46 to the upper winding of relay'41. "When station 59 next goes to marking, relay 4'! will move to the spacing contact in effect continuing the spacing signal on hub 46 into hub 49 and thence out onto the outgoing terminals 4|. Since relay 48 released when station 59 went marking and relay 41 is now held on its spacing contact, tube 58 eventually opens its plate circuit causing relay 59 to release and again operating relay 6| efiectively opening the connectionbetween hub 45 and the winding of relay41. Since the operator at station 59 recognizes the break and in accordance'with trafiic instructions ceases to operate his transmitting 1contacts- 54, a steady marksig; nal is impressed on the outgoing terminals'4l which eventually arrives at the station which initiated the break. The attendant at that station' thereupon releases, his break keyand the space signal entering incoming terminals 49 changes to mark, releasing relay 62, which immediately opens the plate circuit of tube 63 allowing'relay 60 to release and in turn release relay 6| again closing hub 46 to the windingof relay 41., Thejstation which originally broke Relay 6| through its upper armature opens the circuit for relay 4! so that It should be noted that by means Thus it .will appear that tube 58 may be considered a fast-operating slow-releasing relay and tube 63 may be considered a slow-operating fastreleasing relay.

. In the same manner that relay 6!) will respond to a break it will respond to any prolonged spacing condition on incoming terminals 40. Should trouble occur so that relay 6!] is maintained energized for some time relay 64 which may be timed to respond in, let us say, ten seconds will operate an alarm 83. This will notify an attendant that trouble has developed.

In Fig. 4 there is shown a broken-line rectangle indicating the receiving part of a teletypewriter machine. Here, asin Fig. 2, there are two lugs 66 and 61; 66 operates only on the letters signals and 61 operates on all other signals. This machine is operated from the incoming hub 46 through the back contact and lower armature of relay 59 and the polarized relay 68 which in turn operates the receiving magnet 69. If a hit or useless traveling impulse periodically operates the magnet 69 the lug 66 will periodically close a circuit from battery through the. lower armature and back contact of relay H and the stepping magnet 13. This will cause the switch arm 14 to advance step by step. After the arm 14 has moved off normal, the lug 15 will cause the olfnormal switch to close. The immediate effect of this is to place ground on the inner armature of relay 16 and to connect the release magnet 1'! to the front contact of the upper armature of relay 1|. Therefore, if the traveling hit or "letters signal is followed by some other recognized signal, which will operate the lug 61, the grid of the vacuum tube 10 is rendered positive with the consequence that relay H is operated and ground on its upper armature causes the operation of release magnet H to return the switch arm 14 to normal. If, however, this hit or traveling useless impulse continues to be received and continues to periodically operate the lug 66 the switch arm 14 will advance step by step until it strikes a ground connection which may be placed on any contact so as to appropriately time this operation. Thereupon the relay [6 is operated and locks through its inner upper armature to ground on'the offnormal contacts. Relay 16 also closes a circuit from ground, the upper armature and back contact of relay H, the outer upper armature of relay ?6 to the winding of relay 6| which efiectively opens the ring circuit to stop transmission of this traveling impulse further than this particular station circuit. Relayfil in turn places a ground on therelease magnet T! to return the switch arm 14 to normal but relay 16 being slow to release maintains relay Bl operated long enough to sup press the hit.

When the switch arm 14 returns to normal and the off-normal switch is operated to the position shown by lug "15, relay 15 is released and this in turn results in the release of relay 6| so that the ring circuit is again efiectively closed at the back contact and upper armature of relay 6|.

Tube 10 is equivalent to a fast-operating slow releasing relay due to the use of the'timing circuit including condenser 12 and resistance 84. During regular transmission tube 10 will therefore keep relay 7| energized and even a series of letters signals will maintain this tube activated through the lower, armatur and front contactof relay 1|. Thus this circuit will act to clear out an unwanted traveling space signal but will not interfere with legitimate transmission of even a series of letters signals which might otherwise appear to be a traveling hit.

Fig. may be substituted for Fig. 4 by changing the connections at the broken line marked XX. With this arrangement spacing and mark ing signals transmitted by the relay 45 into hub 46 will be transmitted over the back contact and outer left-hand armature of relay 99 to the lower winding of polarized relay 9|, which latter relay will follow the impulses, even in the case of a short pulse, that is, one of such duration that the brush 92. will still be on the start segment 99 when it ends. At the end of such a hit the arrangement of Fig. 5 will effectively open the ring circuit and clear it out in the following manner. When relay 9| goes to its left-hand or spacing contact, ground will be connected through the armature and spacing contact of relay 9|, the outer left-hand armature and back contact of relay'94, the armature and front contact of relay 95 where it will result in short-circuiting the right-hand winding of this relay and the winding of latching magnet 99. Relay 95 and latching magnet 99 will release and the brush 92 will begin to travel according to the well-known practice in the art of stop-start distributors. Since this hit isv of short duration the relay 9| will be moved to its marking contact before the brush 92 has left the start segment 93 whereupon a circuit will be established from battery, the back contact and inner left-hand armature of relay 94, the righthand contact and armature of relay 9|, the outer left-hand armature and back contact of relay 94, the armature and back contact of relay 95, ring 91, brush 92, start segment 93 to the grid of tube 98. This plus battery placed on the grid of trigger tube 98 causes the energization of relay 94' whose circuit may be traced through the back contact and right-hand armature of relay 99, the outer left-hand armature and back contact of release relay I90, the back contact and right-hand armature of relay 99 to battery. Relay 94 now makes a direct connection of plus battery through the alternate contacts of the outer left-hand armature of relay 94 to the armature of relay 95 and thence over the circuit previously traced to the. distributor ring 91. At the same time, relay 94 removes the armature of relay 9| from connection to'the armature of relay 95 so that this relay will have no more influence over the distributor ring 91. 7

Relay 94 through its inner right-hand armature energizes the peg count register I99 so that a count may be made of the number of such hits as they occur. At the same time relay 94 closes a ground connection to the right-hand winding of relay I92 which becomes energized and looks through its front contact and inner' right-hand armature to ground on the back contact and outer right-hand armature of relay I99. Relay I02 in operating operates a peg count register I93 and at the same time closes ground to conductor I94 leading to relay 9|. Relayfil, therefore, operates and efiectively opens the ring circuit. This condition will be maintained, as will appear, for a period somewhat greater than the propagation time of the ring circuit. Relay I92 also removes a battery connection from conductor I95 thereby releasing any one of relays I09 to 5 which may be operated. e

As. the brush 92 passes over the segments |2| to I25 any pair ofrelays, such as I29 and I21 or During the time that relay I I8 is operated and relay I I9: is non-operated the shunt around the left-hand winding of relay is open and this relay operates and looks through its right-hand winding tov battery through the alternate contacts of the outer left-hand armature of relay 94. The latch magnet 99 also operates in parallel with the left-hand winding of relay 95 and prepares to stop the brushes when they arrive at their original position.

With relay I I9 operated the circuit of slow-release relay I 2 9' is opened with a result which will be presently noted. 'Relay H9 also closes a circuit from ground, the outer right-hand armature and'frontcontact of relay H9 and thence in series through the armatures and back contacts of relays I35, I93, I31, I29 and I21 from whence it is extended by the outer right-hand armature and front contact of relay 94 to the right-hand winding of relay I39. Relay I|9 also again shunts the left-hand winding of relay 95. Vfhen relay I29 finally releases it places a short circuit about the winding of relay H9 which releases and thereby opens the circuit of relay I I9 so that this'rel'ay in turn releases and again causes the energization of relay I29.

Relay I36 in operating locks to the back contact of relay 99 and therethrough to ground at the back contact of relay 99. Relay I39 also extends the armature of relay 9| through the back contact and outer left-hand armature of relay 99 to the winding of relay I31.

When the spacing signal caused by the hit has traveled around the'ring circuit and again appears on the hub 49 it. causes relay 9| to operate and this now causes the operation of relay I31. Relay I31 in operating new places a ground on the other terminal of relay 99 so that during the time relay 9| has its armatures on its spacing contact relay 99 is short-circuited. At the end of the spacing signal, relay 9| moves to its marking contact and relay-99 is caused to operate in series with relayl I31. Relay 99 operated (1) opens the locking path of relay I39 which releases, (2) makes thegrid of tube I93 less negative causing relay |99to operate, and (3) opens the plate circuit of tube 98 which allows relay 94 to release. Tube 98 is known as a trigger tube and it only takes a short energization of the grid in order to start sufficient current flowing to cause the energization of relay 99 and this in turn will continue to flow after the energizing impulse'has ceased. Therefore, it is not until the circuit of relay 94 is opened at the back contact and right-hand armature of relay 99 that the tube 99 will cease to function.

With relay 94 released the control of relay 95 and latch magnet 99 is restored to the armature of relay 9| and the peg count register I9I is released. Relay I92 is now also released since the original energizing circuit of its right-hand winding is opened by the relay 94 and the locking circuit is opened at the back contact of the release relay I99. Relay I92 in releasing releases peg count register I93 and at the same time allows relay 6 to become deenergized so as to again effectively close through the ring circuit. Thus the ring circuit has been opened and closed again after a single repetition of a hit. 7

Release relay I in operating causes relays I31 and 99 to-release allowing the grid of tube I38 to become sufficiently negativeiin a fewsecends to cause relay I00 to release restoring the circuit to its former condition. Should a spacing signal be transmitted around the ring'which corresponds to the code for the letter V this will mean that relay 9I goes to spacing and remains in this condition until after the brush 92 has passed over the segment I2I.

' In this case trigger tube 98 is not caused to operate but a ground connection from the spacing contact of relay 9I- is connected through segment I2I .to the winding of relay I26 and thence to battery. Relay I26 operates and prepares a circuit for relay I21. As soon as the brush 92 leaves segment I2I relay I21 comes up in series with re.- lay I26; The other pairs of counting relays are not affected except that any pair which was previously operated will be caused to release at this time. The pair of relays II 8 and II9 are operated as hereinbefore described. In this instance, however, since relay I2'I has moved its armature relay I36 will not be operated but instead 'a ground will be placed through the left-hand armature. and back contact of relay II4 through the winding of relay II thence through the lefthand winding of relay. I I4, the outer right-hand armature and back contact of relay I02, the back contactand inner right-hand armature of relay I00 to battery. Relay II5 alone will operate in this circuit due to the resistance of the winding of relay II5. However, relay II5 closes a ,circuit for the right-hand winding of relay II4 which becomes effective when relay II9 releases. At this time with current flowing through both the windings of relay I I4 this latter relay becomes energized.

On the receipt of a second V signal relay I I 9 again connects a ground pulse to the left-hand armature of relay II 4 whereupon relay H5 is shunted and releases. Thereupon a circuit is established from ground at the armature, and back contact of relay II5, the front contact and right-hand armature of relay II4 through the winding of relay I39. When relay II9 releases and therefore removes ground from the left-hand armature of relay II4 this relay now being held through its left-hand armature releases. Thereupon relay I39 remains energized in a circuit through its winding, the left-hand winding of relay I02, the armature and front contact of relay I39 to ground at the back contact and outer right-hand armature of relay I00. With relay I02 operated relay BI operates and effectively opens the ring circuit so that on the third receipt of the code signal for the letter V this code will be received by relay 9|, but will not be repeated into the outgoing hub 49. Brush 92 rotates a third time and when'relay II9 becomes operated a; ground will be extended from the outer right-hand armature and front contact of relay II9 through the outer left-hand armature and front contact of relay I02 to the right-hand winding of'release relay I00 which therefore becomes operated. With relay I00 operated relays I02 and I39 are'released, in turn causing relays 0|, I00 and the register I03 to release. 'W'hen relay II9 releases, relay I00 will also release thus restoring the circuit to normal.

In the event that a letters signal is received this means that relay 9| will go to its spacing relays.

contact for a period long enough to allow brush 92 :to move oif the'start segment leaving the trigger tube 98 unaffected but relay 9I will again be on its marking contact when segment I2I is reached. Also the relay 9| will be on its marking contact as the brush 92 passes over the segments I22, I23, I2 3 and I25 so that all of the counting relays I20 to I35, inclusive, if in an operated condition, will be released. Hence when relay II9 operates it connects one ground pulse through the outer right-hand armature and back contact of relay 94 to the counting relays I00 and I0'I.

The arrangement of-counting relays, such as relays I09 to H5, inclusive, is well known and the manner of interconnecting them to get various counts is also well known. With the number here provided a maximum of sixteen.letters' signals may be counted and then relay I39 will be operated. The connections shown provide for counting seven letters signals.

/Vnen relay H9 again operates, relay I0'I'wil1 operate for a fourth time causing relay I39 to operate, and when relay'II9 then releases relay I95 will operate allowing relay I02 to operate in series with relay I39 as previously described and the ring circuit will be opened as before. I02 operated also releases all operated counting on'receiving the eighth letters signal, the operation of relay II 9 will cause relay I00 to operate through its right-hand winding in turn releasing relays I 39 and I02 and restoring the circuit to normal.

Thus it will be seen that this circuit will effectively open the ring circuit after one reception of a short hit, after a second repetition of a V signal and after a predetermined number of repetitions of a letters signal.

On all signals other than V and letters theoperation of relay I I9 .causes relay I00 to operate from the plate of tube I38.

number of repetitions of the incoming letters signal. As stated above, the particular connection shown in Fig. 5 is that in which terminals A and B are strapped together, terminalsE and G are strapped together and terminals H and L are strapped together so that relay I39 will oper ate after seven repetitions of the letters signal. In the chart the heavy lines indicate just when the various relays are operated and the relays I39, I92 and I 00 are shown as operated when I the strapping indicated in the column headed by the numeral I of the line Number of repetitions is used. Any alternative strapping will cause relays I39, I02 and I00 to operate at corresponding times.

What is claimed is:

1. In a signaling system, a station circuit havingincoming and outgoing terminals normally connected for through transmission, means connected to said incoming terminal for differentiating between normal signals and recurring stray Relay At the next rotation of the distributor 7 Relay I00 operated restores all counting relays and causes During the period the signals, and means responsive to actuation of said means by stray signals for suppressing said stray signals only after said stray signals have passed through said station circuit a'predetermined number of times.

2. In a signaling system, a station circuit having incoming and outgoingterminals normally connected for through transmission, means connected to said incoming terminal for differentiating between normal signals and recurring stray signals, and means controlled by said first-named means for opening said normal connection between said terminals only after said stray sig nals have passed through said station circuit a predetermined number of times.

8. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, receiving apparatus connected to said incoming terminal,

means in said receiving apparatus for differentia ating between signals of different types, and means responsive to the reception of signals of a particular type only after a predetermined number of successive repetitions thereof for opening said normal connection between said terminals. I

4. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, receiving apparatus connected to said incoming terminal, said receiving apparatus having decoding means for diiferentiating between signals of one type and signals of other types, a stepping device, means responsive to signals of the said one type and to stray disturbances simulating signals of the said one type for operating said stepping device, and means operated by said device when it reaches a predetermined position for opening said normal connection between said terminals.

5. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, means connected to said incoming terminal responsive to stray signals only after being repeated a predetermined number of times for opening said normal connection between said terminals, and means for maintaining said open connection for a predetermined length of time thereafter.

6. In a signaling system, a station circuit having incoming and outgoing terminals normally connected in a tandem ring circuit for through transmission, means connected to said incoming terminal responsive to stray signals only after being repeated a predetermined number of times for opening said normal connection between said terminals, and a slow-releasing instrumentality for maintaining said open connection for a period greater than the propagation time of said tandem ring circuit including said station circuit.

'7. A signaling system comprising a transmission circuit in a closed ring including a plurality of serially connected station circuits and including other devices and apparatus, all combining to establish an over-all definite and measurable propagation time, each said station circuit having incoming and outgoing terminals normally connected for through transmission, means for differentiating between normal signals 'and stray signals traversing said station circuit, and slow-releasing means responsive to said difierentiating means for opening said terminals and maintaining such open connection for a period greater than the propagation time of said closed ring.

8. A signaling system comprising a transmissioncircuit in a closed ring including a plural ity of serially connected station circuits and including other devices and apparatus all combining to establish an over-all definite and measurable propagation time, each said station circuit having incoming and outgoing terminals normally connected for through transmission, receiving apparatus connected to said incoming terminal, transmitting apparatus associated with said outgoing terminal, and means responsive to signals from said transmitting apparatus for opening said normal connection between said terminals and at least one'of said stationv circuits having additional means comprising means for differentiating between normal signals and stray signals, and means responsive thereto for opening said normalconnection between said terminals and maintaining such open connection for a period greater than the propagation time of. said closed ring when stray signals have successively traversed said station circuit a predetermined number of times.

9. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, means connected to said incoming terminal for differentiating between normal signals and recurring stray signals, means responsive to operation of said means for suppressing said stray signals only after said stray signals have passed through said station circuit a number of times, and adjustable means for predetermining said number of times.

- 10. In asignaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, means connected to said incoming terminal for differentiating between normal signals and recurring stray signals, means responsive to operation of said first-named means for suppressing said stray signals only after said stray signals have passed through said station circuit a predetermined number of times, and means for rendering said last means unresponsive to stray signals.

11. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, means connected to said incoming terminal for differentiating between normal signals and recurring stray signals, means responsive to the operation of said first-named means by stray signals for suppressing said stray signals after said stray signals have passed through said station circuit a predetermined number of times, and means responsive to normal signals followed thereafter by stray signals passing through said station Within a predetermined time for rendering said last means inoperative.

12. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, devices connected to said incoming terminal for differentiating between normal signals and recurring stray signals, means responsive to operation of said devices by stray signals for suppressing said stray signals only after said stray signals have passed through said station circuit a predetermined number of times, and a delayed action instrumentality for preventing the operation of said last means, said instrumentality being responsive to normal signals and to stray signals closely following normal signals.

13. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission,

means connected to said incoming terminals responsive to a particular signal, variably adjustable means for counting the number of times said signal passes successively through said station circuit without other intervening signals, and means responsive thereto only when the count has reached a predetermined point for preventing further passage of said stray signal.

14. In a signaling system, a station circuit having incoming and outgoing terminals normally connected for through transmission, means connected to saidincoming terminal responsive to a particular signal, variably adjustable means for counting the number of times 'a said signal passes through said station circuit, and means responsive thereto only when the count has reached a-predetermined point for suppressing said signal, and means responsive to one of other signals for returning said counting meansto its starting point.

15. In a signaling system, a station circuit v a single impulse for counting the number of repetitions of said impulse, means" variably re-' sponsive thereto for operating said first means, and means responsiveto the character of said single impulse for controlling the variable re-' sponse of said last means. 7

17. In a signaling system, a station circuit having incoming and outgoing terminals' normally connected for through transmission, means for opening said normal connection, means responsive to the repeated reception of a single impulse for counting the number of repetitions of said impulse, means variably responsive thereto for operating said first means,

means responsive to the character of said single impulse for controlling the variable response of said last means, and means responsive to the reception of normal'signals for preventing ,the operation of said first means.

18. In a permutation code transmission system for transmitting a plurality of units in permutated groups having an equal number of units per group, each unit consisting of one or another of more than one possible condition, a station circuit having incoming and outgoing terminals, means connecting said terminals to said given number.

ALLEN R. BONORDEN. 

